title: Determination of the molecular mass and dimensions of membrane proteins by size exclusion chromatography.
abstract: Size exclusion chromatography is an established technique for the determination of hydrodynamic volumes of proteins or protein complexes. When applied to membrane proteins, the contribution of the detergent micelle, which is required to keep the protein soluble in the aqueous phase, needs to be determined to obtain accurate measurements for the protein. In a detergent series, in which the detergents differ only by the length of the alkyl chain, the contribution of the detergent micelle to the hydrodynamic volume is variable, whereas the contribution of the protein is constant. By using this approach, several parameters of membrane proteins can be estimated by extrapolation, such as the radius at the midpoint of the membrane, the average radius, the Stokes radius, and the excluded volume. The molecular mass of the protein can be determined by two independent measurements that arise from the behaviour of the free detergent micelle and protein-detergent micelle during size exclusion chromatography and the determination of the detergent-protein ratio. Determining the dimensions of protein-detergent micelles may facilitate membrane protein purification and crystallization by defining the accessibility of the protein surface.
authors.affiliation: The Medical Research Council, Dunn Human Nutrition Unit, Hills Road, Cambridge CB2 0XY, UK. ek@mrc-dunn.cam.ac.uk
authors.forename: Edmund R S
authors.initials: ER
authors.lastname: Kunji
authors.forename: Marilyn
authors.initials: M
authors.lastname: Harding
authors.forename: P Jonathan G
authors.initials: PJ
authors.lastname: Butler
authors.forename: Pearl
authors.initials: P
authors.lastname: Akamine
mesh_terms: D000818:Animals; D002417:Cattle; D055598:Chemical Phenomena; D002850:Chromatography, Gel / Q000379:methods*; D003902:Detergents / Q000737:chemistry / Q000494:pharmacology; D005960:Glucosides / Q000737:chemistry / Q000494:pharmacology; D057927:Hydrophobic and Hydrophilic Interactions; D008565:Membrane Proteins / Q000737:chemistry* / Q000302:isolation & purification; D008823:Micelles; D000226:Mitochondrial ADP, ATP Translocases / Q000737:chemistry* / Q000302:isolation & purification; D008958:Models, Molecular; D008970:Molecular Weight; D029701:Saccharomyces cerevisiae Proteins / Q000737:chemistry / Q000302:isolation & purification
chemical_list: C534456:Aac3 protein, S cerevisiae; D003902:Detergents; D005960:Glucosides; D008565:Membrane Proteins; D008823:Micelles; D029701:Saccharomyces cerevisiae Proteins; D000226:Mitochondrial ADP, ATP Translocases